12AU7

[wolfgang6505]

Hello folks, I haven't posted in a while. I decided not to sale my DC-5. I love the thing and it sounds great and all of my previous problems with it are fixed. i just can't say enough about the amp, it really really has a great sound.

One thing I'd like to ask is, has anyone here ever replaced the 12AX& in the the V1 position to a 12AU7 for less gain. I was talking to my amp tech and he said if I wanted the amp to have less gain overall to try changing the 12AX7 to a 12AU7 in the V1 spot. He said just to try it and see if I liked it. I don't wanna buy a 12AU7 if I'm not gonna be satisfied with the change in sound. I play alot of rockibilly stuff like Danny Gatton and also have been doing more country stuff so I don't need all that much gain. I have another amp I can use for heavey rock sound if the change cleans the mesa up a good bit.

I was just wondering if anyone has tried this swap in tubes before. Any input is better than none so I just figured I'd ask
Thanks-wolf

 

[GregN]

I haven't done it w/ my Mesa but I have done it in other amps and it will definitely clean up the amp. 12AU7's aren't very expensive so you should try it if you're looking to reduce the gain.
Also, what in the heck are you talking about in your "Boob Tube" thread?? I'm clueless!

 

[brianf]

Go 12AT7 first. Then the 12AU7 and 12 AY7. Preamp tubes are cheap. It's fun to experiment.

brianf

 

[wolfgang6505]

Ok I'll try a few, might aswell. I'm sure I'll find what I'm looking for if I buy all three 12AT7,12AU7, and a 12AY7.

I'm sorry about the boob tube thing LOL, hahahaha....

Those tops that women wore that didn't have straps, they just covered there boobs LOL. It real wasn't an important post at all I was just having a little debate with the wife about it and wanted to post and see if anyone knew...it real isn't important though LOL.

-Wolf :lol:

 

[marshman]

Well, I'm far from the expert, but you will definitely reduce your up-front gain with a 12AU7 significantly. Without being too technical (because I can't), a 12AX7 has a gain rating of 100. The 5751, only available NOS as far as I know, runs 70. 12AT7 runs 60. 12AY7 is rated for 44 and 12AU7 is about 20. I don't think you wanna drop anything lower than a 12AT7 in V1, as that would just about kill your tone. Early Fender bassman amps came with a 12AY7 in V1, but they were deliberatly going for low distortion. Brian was right. Modern production pres are pretty cheap, give a few a try and see what you like. Downside is, that if you buy 5 different 12AX7 from 5 different manufacturers, they'll all sound different, making it harder to pick. Check this out:

http://www.torresengineering.com/realinonprea.html

Oh, and the "Boob Tube" is the Television. You're referring to a 'Tube Top'. But then again, I was 8-ish when they were popular, so maybe my mom lied to me about the name.

 

[wolfgang6505]

LOL...marshman you're all right...lol

Thanks for the post, I never knew anything about the pre tubes ratings like that, I'm going to try a 12AT7 first, and I'll try to stick with sovtel seeing as all the tubes in there now are sovteks.

 

[axwielding1]

If you look through the 12AT7's, find a good one with a "halo" getter, rather than the typical "pan"... I found a GT with this getter, and it sounds great...
I also suggest the 5751... I bought a blackplate JAN GE 5 star for $30, and man, this thing is awesome... The big difference is the harmonics... They jump right out. The tone is fat as well, and the bit of gain you get is really nice...I swear, you'll love it....Search "5751" on ebay.. I think the seller is "vintagevalveset" who is great, and has some awesome tubes....
Check 'em out... The GT12AT7 I bought was $13, so it's not much more to get NOS, plus, It'll last ALOT longer, and will probably close to balanced, and test higher than new......
ax. 8)

 

[LHanson]

I run a 12au7 in V1 of my .50 cal +. Still has PLENTY of gain (Santana-like), and opened up the clean settings quite a bit.

Troll around a bit, get NOS, it's worth it.